In each of electronic systems, a connector is functioned as a basic element which is necessary for forming an integral system and performs electrical connection and signal transmission between devices, between elements, or between systems. Therefore, in order to be more competitive in market, all manufacturers make efforts in discrete design or optimization for a detail structure of each of components of the connector, to increase flexibility of modularization of each of components and meet the demand for function and structure of the connector. Generally speaking, most of the existing connectors are fastened on the circuit board by soldering, to transmit electric power or digital data with circuits on the circuit board. Because of different usage demands and environments for various electronic devices, the manufacturers also develop various types of the connectors which are adapted for the electronic devices having specific demands. For example, a waterproof connector is a kind of connector to mainly protect the circuit board from being penetrated by outside moisture to impair a normal operation of the circuit board.
An illustration for the existing waterproof connector is described in following paragraph. Please refer to FIG. 1 and FIG. 2. It is particularly noted that a front direction is defined at top-right side of the FIG. 1, a back direction is defined at down-left side of the FIG. 1, a right direction is defined at down-right side of the FIG. 1 and a left direction is defined at top-left side of the FIG. 1 for convenient illustration. The waterproof connector 1 includes an outer housing 11, an inner casing 12, a terminal block 13 and a waterproof glue layer 14. A front end and a rear end of the outer housing 11 are communicated with each other to form a first accommodating space 110. The inner casing 12 can be mounted into the first accommodating space 110 via a rear end of the outer housing 11 to be assembled inside the outer housing 11. A front end and a rear end of the inner casing 12 are communicated with each other to form a second accommodating space 120. The inner casing 12 is further provided with two grounding pins 121 protrudingly disposed at the rear end thereof. When the inner casing 12 and the outer housing 11 are assembled, the grounding pins 121 are extended out of the rear end of the outer housing 11.
Please refer back to FIG. 1 and FIG. 2. The terminal block 13 is made of isolation material and provided with a plurality of through holes 130 at a rear end thereof and a tongue plate 131 protrudingly disposed at a front end thereof. The tongue plate 131 is provided with a plurality of slots 132 concavely disposed thereon. The slots 132 are communicated with the through holes 130, respectively. The terminal block 13 can be mounted into the second accommodating space 120 via the rear end of the inner casing 12 to be assembled inside the inner casing 12, a plurality of connection terminals 16 are inserted into the terminal block 13 via the through holes 130 respectively, front ends of the plurality of connection terminals 16 are accommodated in the slots 132 respectively, and rear ends of the plurality of connection terminals 16 are exposed out of the rear ends of the terminal block 13 and the inner casing 12. Moreover, after the outer housing 11, the inner casing 12 and the terminal block 13 are assembled integratedly, the manufacturer watertightly fills the waterproof glue layer 14 (as shown in FIG. 2) in the rear ends of the outer housing 11, the inner casing 12 and the terminal block 13, to prevent moisture which is entered via the front ends of the outer housing 11 and the inner casing 12 from leaking out of the rear ends of the outer housing 11 and the inner casing 12. Therefore, the moisture can be efficiently prevented from impairing the circuit board at the rear end of the waterproof connector 1 to cause short-circuit or damage of circuits or electric devices on the circuit board and further cause operation failure of the circuit board.
Please refer back to FIG. 1 and FIG. 2. The grounding pins 121 of the inner casing 12 is penetrated the outer housing 11 and the waterproof glue layer 14 and exposed out of the outer housing 11 and the waterproof glue layer 14, whereby the manufacturer can solder the grounding pins 121. However, during the soldering process, because the grounding pins 121 have larger volume, the manufacturer needs spend more time for heating. The grounding pins made of metal material have better thermal conductivity, so watertightness of the waterproof glue layer 14 near the grounding pins 121 is impaired due to thermal expansion and contraction, and it causes that the waterproof glue layer 14 is hard to efficiently block moisture. Therefore, what is needed is to improve the traditional waterproof connector for solving above-mentioned problems.